750mm Circle Sign Faces

What a circle means

Shape carries meaning on a UK road sign before the legend is read, and a circle always gives an order rather than a warning.

• Blue circle: a positive instruction. Keep left to diagram 610, turn right, left and right turn ahead, and the mini roundabout sign to 611.1 all tell a driver what they must do.
• Red ring on white: a prohibition. No entry, no left turn to 613 and no right turn to 612 tell a driver what they must not do.
• Red ring with a number: a speed limit.

Triangles warn, circles order, rectangles inform. Keeping that straight is the fastest way to check a layout before it goes out.

Speed roundels, and which ones are legal where

The 20, 30, 40 and 50mph faces are statutory speed limit signs for use on the public highway under a traffic order. The 5mph and 10mph faces are not, because speed limits on a public road cannot be set below 20mph.

That does not make the low roundels useless, it places them: private roads, car parks, depots, site compounds, distribution yards and holiday parks, where the operator sets the site speed limit and enforces it as a condition of access rather than as a road traffic offence. Order them for a yard, not for a street.

Directing traffic past works

Keep left and keep right are the workhorses of this group. They go on the approach face of an obstruction, an island or a closed lane, and they are the sign a driver actually steers by. Turn left, turn right, and the left and right turn ahead signs handle a diversion at a junction, giving notice on the approach and the instruction at the turn.

Where a route change is more than one turn, the circular signs handle the movement and a rectangular sign carries the route message. They work as a pair, not as alternatives.

Mounting a circular face

A 750mm circular face mounts on a 750mm square frame. That catches people out when ordering, because the frame is listed by its square dimension rather than by the diameter of the face it holds. The steel A-frame stanchion takes 750 x 750mm faces in 3mm plastic or aluminium, stands the sign at working height, and is weighted at the base with sand bags for stability.

Faces are pressed steel with a zinc coating under the print, finished with an RA1 grade reflective film, and are sold either on their own or complete with the frame and clips.